Abstract: In an electronic stethoscope which includes a pickup head, a microphone, a tubular accoustic connection between the pickup head and microphone, an amplifier receiving an input from the microphone, a speaker coupled to the output of the amplifier, a binaural headpiece and tubes acoustically coupling the output of the speaker to the binaural headpiece, there is included a switch by means of which a momentary on operation can be achieved and a timer responsive to the switch to couple power to amplifier circuit, the timer adapted to shut power off after a predetermined period of time. Preferably the amplifier is an integrated circuit operational amplifier with a filter circuit which brings up lower frequencies interposed between the amplifier and speaker.

Abstract: A hearing aid having an earplug that is inserted wholly within the auditory canal of the ear of a user to leave the concha portion of the user's ear exposed for the collection of sound waves for transmission to a microphone as located in the outermost end of the ear plug; the component parts of the hearing aid being wholly contained within the ear plug, thereby avoiding the use of the conventional exposed tubing, wiring and behind-the-ear housing which normally contains the hearing aid controls therein, a cover member being pivotally mounted on the outer surface of the earplug for concealing the controls thereon and for effecting a smooth uninterrupted outer surface that is aesthetically pleasing as located in the user's ear, and a barrier being provided in the earplug for locating the sound tube of the hearing aid in an insulated chamber to insure fidelity of sound as transmitted to the auditory canal of the user.

Abstract: A barrier gate isolated channel charge coupled device integrated circuit imager which permits the barrier gate to define the transfer channel from an inner shift register to an outer shift register to the exclusion of the field oxide layer. By extending the length of the barrier gate slightly and bringing the storage gate down and out around each barrier gate, and widening the field oxide dimension, relative to one another, the buried channel potential voltage remains high allowing for more efficient charge transfer or, if desired, the isolated channel dimension can be decreased while still maintaining a high minimum buried channel potential voltage.

Abstract: A support for a one-piece telephone of a type incorporating in a single body all the equipment of a conventional two-part telephone, such as the apparatus, and the switch hooks normally positioned on or under the cradle for switching off the telephone when the handset is replaced. The support comprises a back plate having inclined end portions, one at an acute angle and the other at an obtuse angle with respect to the back plate, the former serving as an abutment for the switch hooks of the telephone, to actuate them to turn off the telephone automatically when it is replaced on the support, and the latter cooperating with a central saddle-like projection to define a cradle into which the earpiece of the telephone can be fitted and retained by means of slight flexure which is permitted by the material of which the device is made, that is a slightly resiliently or semirigid material such as a foamed plastics, rubber or the like.

Abstract: Disclosed is an electroacoustic transducer structure which can be formed in a semiconductor substrate and incorporated as part of an integrated circuit, and which provides a built-in dc bias for operation. An appropriate density of fixed charge is provided in an insulating layer adjacent to one of the electrodes in the gap between electrodes. Methods of manufacture are also disclosed including means for introducing the charge by contacting the insulating layer with a liquid medium, plasma charging, or by ion beam implanting into the layer.

Abstract: Prior art magnetic chuck control systems do not utilize state of the art components and do not sufficiently isolate the power output from control circuits. The instant invention discloses a magnetic chuck control system employing solid state circuitry including a power output circuit (24) adapted to apply a DC voltage to an object such as a magnetic chuck (12) or the like so as to magnetize the same. The power output circuit employs a triac reversing circuit and is interfaced with a digital control circuit (26) and a digital-to-analog converter circuit (30) so as to apply alternating polarity voltage signals of successively reduced magnitude to the chuck during a demagnetizing operation. All high voltage is confined to the power output circuit so as to provide significant safety protection to the operator.

Abstract: In a phased-array sound pickup apparatus microphones are divided into a first and second subarrays, the microphones of the first subarray having individual unidirectional response patterns oriented on one side of the normal to the array and the microphones of the second subarray having their response patterns oriented on the other side of the normal so that the array's main lobe assumes different orientation from the orientation of the microphone's individual response patterns so that the array's unwanted back lobe falls outside of the microphone's response patterns. The microphones may be grouped into a plurality of pairs and the signals from the paired microphones are mixed so that different individual response patterns are generated in correlation with the array's main front lobe to cause the unwanted back lobe to occur outside of the individual response patterns.

Abstract: A pickup device for picking up sound generated by the vocal chords and transmitted through bones from the nasal bone. A microphone (11) is mounted on or embedded into an eyeglass-like assembly (13, 15). When the microphone is mounted as a nosepiece, it is made into direct contact with the nose so that it directly picks up vibration transmitted through the nasal bone. When the microphone is mounted on the eyeglass-like frame or embedded therein, it picks up vibration transmitted through the nosepieces and eyeglass-like frame. A cord (12) whose one end is electrically connected to the microphone is held by holding member extended from the eyeglass-like assembly (13, 15) so that the transmission of mechanical vibration to the microphone is prevented.

Abstract: An improved in-the-ear hearing aid. The earmold is divided into two separate chambers defined by a divider wall. A first chamber has an opening adjacent the outer ear and the second chamber has an opening adjacent the ear drum. A microphone is positioned adjacent the first chamber opening. An amplifier and a battery for its power source are located within the first chamber. A receiver with a sound emitting aperture is located within the second chamber. The sound emitting aperture is directed toward the divider wall. The receiver is completely surrounded by an acoustic resistance material which separates the receiver from the walls of the chamber. The microphone, amplifier, battery and receiver are electrically interconnected for supplying to the receiver amplified microphone signals. The combination of the dimensions of the chamber and the acoustic material provide a horn effect to the receiver produced sound. The opening of the second chamber may be covered with a removable grill.

Abstract: An electromechanical magnetic transducer with a moving armature having (1) substantially pure translational adjustability, or (2) adjustability characterized by a substantially definite pre-chosen ratio of rotation to translation. The armature comprises an armature leg and an armature support yoke having plastically deformable yoke arms. A yoke arm comprises a pair of struts that are mutually inclined to provide a toggle-like action upon application of an adjusting force, such action opposing or enhancing the tendency of the support of the armature leg to rotate.

Abstract: A hearing aid comprising a microphone whose output signal is split by high and low pass filters and supplied to two channels. Each channel includes a variable gain circuit the outputs of which are mixed and supplied to an earphone. The turnover frequencies of the filters are such that one channel limits the dynamic range of vowels whereas the other channel limits the dynamic range of consonents, thus preventing interaction and masking of consonants by preceding vowels. The intelligibility of speech is thus improved.

Abstract: This speaker enclosure is ideal for public address systems. Primarily, it consists of a ceiling mounted panel, with a conical baffle secured to it, which is used to delay sound off of the back of the speaker, so as not to interfere with the sound from the front of the speaker. It further includes a wire screen, which is used to cut down microphone feedback.

Abstract: An apparatus and method for centering a voice coil in a loudspeaker having a vented pole piece. The voice coil centering is accomplished by means of a concentrically located voice coil suspension and an attached cylindrical mounting ring that can be set into a recess, or otherwise positively located on the pole piece. The pole piece is formed in such a way so as to precisely receive a suspension mounting ring and center the voice coil in the magnetic field gap with no further adjustments. This invention permits the use of a pole piece mounted voice coil suspension on a ventilated pole piece.

Abstract: A battery-powered miniature acoustical transducer system for a hearing aid, including a microphone and an amplifier, has a combination filter and voltage regulator incorporated in its power supply circuit; the filter/regulator includes a field-effect transistor having its drain and source electrodes interposed in series between one battery terminal and a first power terminal of the amplifier, a resistor connecting the source and gate electrodes of the FET, a transistor having its emitter and collector interposed in series between the other power terminal of the amplifier and the gate electrode of the FET, and a junction diode connected from the FET source electrode to the transistor base, the diode junction and the base-emitter junction of the transistor both having highly non-linear voltage/current characteristics.

Abstract: The electroacoustic transducer comprises an oscillating element (6, 7) holding a coil (8), the oscillating element (6, 7) being connected to a magnet frame (11-17) by an elastomer ring (10'). The magnet frame (11-17) has two magnets (14, 15) and constitutes an inertial mass. The oscillating element (6, 7) is intended to be attached rigidly by its base plate (6) to a panel (1) so that the sound waves are transmitted to the latter (1) which thus plays the role of a speaker diaphragm. Adjusting screws (27) make it possible to modify the characteristics of the elastomer (10') as a function of the mounting condition and the desired sound diffusion effect.

Abstract: An electro-acoustic transducer capable of operating as an emitter and as a pick-up for acoustic waves in an ambient medium includes a cover member having an opening for communication with the ambient medium, first and second diaphragms which are spaced from each other within the cover member, the second diaphragm being capable of vibrating under the effect of acoustic waves and being disposed between the first diaphragm and the opening in the cover member, an electromagnet for causing vibrations of the first diaphragm in response to electrical excitation signals when the transducer is operating in the emitter mode, an air cushion contained in a closed chamber separating the two diaphragms or a rigid mechanical connection between the two diaphragms for communicating the vibrations of the first diaphragm to the second diaphragm, and a pair of electrodes disposed on opposite sides of the second diaphragm, which is preferably a sheet of electret, for producing an output signal in response to vibrations of the sec

Abstract: A dynamic loudspeaker unit having a voice coil formed with two windings in which a capacitor is connected in series to a parallel circuit, one circuit arm being composed of a series circuit of one of the two windings and an inductor and the other circuit arm being composed of the remaining winding. The dynamic loudspeaker unit thus constructed is housed in a bass-reflex type cabinet, whereby a shoulder characteristic having a large Q in a bass zone can be obtained, and due to a combination of the inductor and the capacitor, a desired lowest resonance frequency lower than an actual lowest resonance frequency can be selected. Thus, the reproducible bass range can be extended.

Abstract: A loudspeaker system comprises a flexible tube with a first loudspeaker mounted within one end and a second loudspeaker mounted within the other end thereof. Each loudspeaker is oriented to direct sound outwardly from the end of the tube in which it is mounted. A baffle plate is mounted within the tube, intermediate the first and second loudspeakers.

Abstract: A protective cover for the push-button array of a push-button telephone set having a planar surface through the push-buttons extend, comprise a flexible elastomeric sheet having at least one recessed portion with side walls forming a pocket which overlies each of the push-buttons on said telephone set and permits individual displacement of the underlying telephone set push-buttons. The sheet has a skirt portion extending laterally beyond the side walls of the pocket and the sheet is continuous between its lateral edges, whereby the entire push-button array is overlaid by the cover and thereby protected against spilled liquids or other environmental hazards. Surrounding the sheet is a metal frame having a channel on the internal periphery into which the sheet extends and is permanently secured.

Abstract: An apparatus and a method modulate a carrier signal so that the resultant modulated signal varies between a value substantially equal to the quiescent level of the carrier signal and peak values up to several hundred percent of the quiescent level of the carrier signal. The apparatus includes an electrical circuit for adjusting the modulating signal so that it is clamped at a reference value to prevent overmodulation. The clamped signal controls a variable resistance mechanism which forms a part of the gain determining portion of a modulator circuit including an amplifier. The amplifier modulates the carrier signal in accordance with the gain determined by the variable resistance. The variable resistance is controlled by the clamped signal so that it causes the gain of the amplifier circuit to vary between approximately one and a value greater than one.